Description : (a) Define a balanced chemical equation. Why should an equation be balanced? (b) Write the balanced chemical equation for the following reaction: (i) Phosphorus burns in presence of chlorine to form phosphorus penta chloride. (ii) Burning of natural gas. (iii) The process of respiration. -Chemistry
Last Answer : Answer. (a) Balanced chemical equation has an equal number of atoms of different elements in the reactants and products. According to law of conservation of mass, matter can neither be created nor be destroyed in a chemical ... C6H12O6 (s) + 6O2 (g) + 6H2O ---> 6CO2 (aq) + 12H2O (l) + energy
Description : The following chelating agent should not be used systemically to treat acute iron poisoning in a child: A. Desferrioxamine B. Calcium edetate C. Dimercaprol D. Calcium disodium diethylene triamine penta acetic acid
Last Answer : C. Dimercaprol
Description : Pseudo halides are anions having resemblance with halide ions. Group I metals can form salts with pseudo halides. Pseudo halogens can acts as ligands
Last Answer : Pseudo halides are anions having resemblance with halide ions. Group I metals can form salts with pseudo halides. ... and C black D. `Na(CN)_2^-`
Last Answer : Pseudo halides are anions having resemblance with halide ions. Group I metals can form salts with pseudo halides. ... NaBr C. (C) NaF D. (D) Nal
Last Answer : Pseudo halides are anions having resemblance with halide ions. Group I metals can form salts with pseudo halides. ... . H_2O` D. (D) None of these
Last Answer : Pseudo halides are anions having resemblance with halide ions. Group I metals can form salts with pseudo halides ... . `NaCN, NaOCN` D. `HCOONa, NH_3`
Description : When ammonia is added to an alkyl halide, in the presence of base : (a) primary amines form (b) amides form (c) nitrated alkyl halides form (d) quaternary ammonium salts form
Last Answer : primary amines form
Description : Alkyl halides react with ammonia in the presence of base to form : (a) primary amines (b) nitrated alkyl halides (c) amides (d) quaternary ammonium salts
Last Answer : primary amines
Description : Which of the following halides has the maximum covalent character ?
Last Answer : Which of the following halides has the maximum covalent character ? A. LiI B. NaI C. KI D. CsI
Description : Best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is
Last Answer : Best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in ... reaction D. Reaction with `NH_(3)`
Description : Number of halides undergoing complete reaction in presence of water under normal conditions is : (i) `BF_(3)` (ii) `BCl_(3)` (iii) `NCl_(3)` (iv) `AlC
Last Answer : Number of halides undergoing complete reaction in presence of water under normal conditions is : (i) `BF_(3)` (ii ... (vi) `PCl_(3)` (vii) `AsCl_(3)`
Description : The order of stability of halides of sulphur with different halogens is
Last Answer : The order of stability of halides of sulphur with different halogens is A. `I^(-) gt Br^(-) gt Cl^(-) gt F^(-)` ... `F^(-) gt Cl^(-) gt I^(-) Br^(-)`
Description : Which of the following hydrogen halides react with `AgNO_3` to give a precipitate that dissolves in hypo solution ? (I)HCl (II)HF (III)HI (IV)HBr
Last Answer : Which of the following hydrogen halides react with `AgNO_3` to give a precipitate that dissolves in hypo solution ? (I) ... II),(I) D. (II),(IV),(III)
Description : The correct order of the thermal stability of hydrogen halides `(H-X)` is
Last Answer : The correct order of the thermal stability of hydrogen halides `(H-X)` is A. (1) HI gt HBrgt HCI gt HF B. ... HBr lt HI D. (4)Hl gt HCI lt HF lt HBr
Description : Which types of mechanism take place in sec-halides, `(CH_(3))_(2)CH-X`?
Last Answer : Which types of mechanism take place in sec-halides, `(CH_(3))_(2)CH-X`? A. `S_(N^(1))` B. `S_(N^(2))` C. `S_(N^(1)) and S_(N^(2))` D. None of these
Description : Which of the following halides will be most reactive towards `S_(N^(2))` reaction?
Last Answer : Which of the following halides will be most reactive towards `S_(N^(2))` reaction? A. `C_(6)H_(5)CH_(2 ... (2)-underset(Br)underset("| ")"CH"-CH_(3)`
Description : The `S_(N^(1))` reactivity of the following halides will be in the order: (i) `(CH_(3))_(3)C-Br` (ii) `(C_(6)H_(5))CHBr` (iii) `(C_(6)H_(5))_(2)C(CH_(
Last Answer : The `S_(N^(1))` reactivity of the following halides will be in the order: (i) `(CH_(3))_(3)C-Br` (ii) `(C_ ... D. (iii) gt (ii) gt (i) gt (iv) gt (v)
Description : The correct increasing order of the reactivity of halides for `S_(N^(1))` reaction is:
Last Answer : The correct increasing order of the reactivity of halides for `S_(N^(1))` reaction is: A. `CH_(3)CH_(2)-Xlt( ... -Xlt(CH_(3))_(2)CH-XltCH_(3)CH_(2)-X`
Description : The order of reactivities of the following alkyl halides for a `S_(N^(2))` reaction is :
Last Answer : The order of reactivities of the following alkyl halides for a `S_(N^(2))` reaction is : A. RF > RCl > RBr > ... RBr > RF > RI D. RI > RBr > RCl > RF
Description : Which of the following alkyl halides is hydrolysed by `S_(N^(1))` mechanism?
Last Answer : Which of the following alkyl halides is hydrolysed by `S_(N^(1))` mechanism? A. `CH_(3)Cl` B. `CH_(3)CH_(2)Cl` ... (2)CH_(2)Cl` D. `(CH_(3))_(3)"CCl"`
Description : The stability of the halides of group 16 elements decreases in the order
Last Answer : The stability of the halides of group 16 elements decreases in the order A. `F gt Cl gt Br gt I` B. `Cl gt Br ... gt Cl gt F` D. `Br gt Cl gt F gt I`
Description : Silver halides are used in photographic plates because they are (a) Oxidised in air (b) Colourless (c) Easily soluble in a hypo solution (d) Readily reduced by light
Last Answer : Ans:(d)
Description : Silver halides are used in photographic plates because they are - (1) oxidised in air (2) soluble in hyposolution (3) reduced by light (4) totally colourless
Last Answer : (3) reduced by light Explanation: The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including ... - meaning that it can undergo development which turns the entire crystal into metallic silver.
Description : Why the presence of a base is essential in the ammonolysis of alkyl halides ?
Last Answer : During ammonolysis of alkyl halides, the acid liberated during the reaction combines with the amine formed to form amine salt. To liberate free amine from the amine salt, a base is needed.
Description : Metal sulphides occur mainly in rocks and metal halides in lakes and seas. Explain.
Last Answer : Ans.: Metal halides being soluble in water, get dissolved in rain water and are carried to lakes and seas during weathering of rocks. On the otherhand, metal sulphides being insoluble are left behind in the rocks as residue.
Description : Give reason for the appearance of colour in alkali metal halides.
Last Answer : Due to F-centres.
Description : Aryl halides are less reactive towards nucleophilic substitution as compared to alkyl halides due to (a) Inductive effect (b) Resonance stabilization (c) Tautomerism (d) Stereoisomerism
Last Answer : Resonance stabilization
Description : Grignard reagents do not show any reaction with (a) Alkoxyalkanes (b) Alkanones (c) Alkyl alkanoates (d) Acyl halides
Last Answer : Alkoxyalkanes
Description : Which of the following halides is least reactive in an E2 reaction with sodium methoxide? (a) (CH3)3CCH2I (b) (CH3)2CHCHICH3 (c) (CH3)2CHCH2Br (d) (CH3)2CHCH2Cl
Last Answer : (CH3)3CCH2I
Description : Which of the following halides is most reactive in an E2 reaction with sodium methoxide? (a) (CH3)3CCH2I (b) (CH3)2CHCHICH3 (c) (CH3)2CHCH2Br (d) (CH3)2CHCH2C
Last Answer : (CH3)2CHCHICH3
Description : Which of the following statements concerning SN2 reactions of alkyl halides is not correct? (a) The rate of reaction depends on the concentration of the nucleophile. (b) The rate of reaction depends on the ... carbon of the C-Br bond. (d) All alkyl iodides react more rapidly than all alkyl chlorides
Last Answer : All alkyl iodides react more rapidly than all alkyl chlorides
Description : Which of the following is not correct concerning substitution and elimination reactions of alkyl halides? (a) The electrophile replaces the leaving group. (b) Compounds containing electron-donating groups bonded to an ... replaced by another atom or group in substitution reactions. (d) (a) and (b)
Last Answer : (a) and (b)
Description : Which alkyl halides react most readily by nucleophilic substitution? (a) CH3CH2Cl (b) CH3CH2I (c) CH3CH2Br (d) CH3CH2F
Last Answer : CH3CH2I
Description : Alkyl halides undergo (a) Electrophilic substitution reactions (b) Electrophilic addition reactions (c) Nucleophilic substitution reactions (d) Nucleophilic addition reactions
Last Answer : Nucleophilic substitution reactions
Description : Whose name is given to alkylmagnesium halides: w) Victor Grignard x) Daniel Rutherford y) Dmitri Mendeleev
Last Answer : ANSWER: W -- VICTOR GRIGNARD
Description : Silver halides are used in photographic plates because they are (1) oxidised in air (2) soluble in hyposolution (3) reduced by light (4) totally colourless
Last Answer : reduced by light
Description : All of the following statements concerning the actinomycetous filamentous soil bacterium Frankia are correct except that Frankia (a) can induce root nodules on many plant species (b) can fix ... its host plant through root hair deformation and stimulates cell proliferation in the host's cortex
Last Answer : (b) can fix nitrogen in the free-living state
Description : Which of the following gases cannot be collected by water displacement? w) Nitrogen x) Oxygen y) Hydrogen z) Hydrogen Chloride
Last Answer : ANSWER: Z -- HYDROGEN CHLORIDE